Your software release may not support all the features documented in
this module. For the latest caveats and feature information, see Bug Search
Tool and the release notes for your platform and software release. To find
information about the features documented in this module, and to see a list of
the releases in which each feature is supported, see the feature information
table at the end of this module.
Use Cisco Feature Navigator to find information about platform support
and Cisco software image support. To access Cisco Feature Navigator, go to
http://www.cisco.com/go/cfn. An account on Cisco.com is
Prerequisites for Ethernet Management Ports
When connecting a PC to the Ethernet management port, you must first assign an IP address.
the Ethernet Management Port
The Ethernet management port,
also referred to as the
GigabitEthernet0/0 port, is a VRF (VPN routing/forwarding)
interface to which you can connect a PC. You can use the Ethernet management
port instead of the
console port for network management. When managing a
stack, connect the PC to the Ethernet management port on a stack member.
Port Direct Connection to a
Figure 1. Connecting a
Switch to a PC. This figure
displays how to connect the Ethernet management port to the PC for a
or a standalone
Port Connection to Stack
using a Hub
In a stack with only
switches, all the Ethernet management ports on
the stack members are connected to a hub to which the PC is connected. The
active link is from the Ethernet management port on the
active switchthrough the hub, to the PC. If the
activeswitch fails and a new active
switch is elected, the active link is now
from the Ethernet management port on the new active
switch to the PC.
Figure 2. Connecting a
Switch Stack to a PC. This figure
displays how a PC uses a hub to connect to a
Port and Routing
By default, the
Ethernet management port is enabled. The
cannot route packets from the Ethernet management port to a network port, and
the reverse. Even though the Ethernet management port does not support routing,
you may need to enable routing protocols on the port.
Figure 3. Network Example
with Routing Protocols Enabled. Enable routing
protocols on the Ethernet management port when the PC is multiple hops away
and the packets must pass through multiple Layer 3 devices to reach the PC.
In the above figure ,
if the Ethernet management port and the network ports are associated with the
same routing process, the routes are propagated as follows:
The routes from
the Ethernet management port are propagated through the network ports to the
The routes from
the network ports are propagated through the Ethernet management port to the
Because routing is not
supported between the Ethernet management port and the network ports, traffic
between these ports cannot be sent or received. If this happens, data packet
loops occur between the ports, which disrupt the
and network operation. To prevent the loops, configure route filters to avoid
routes between the Ethernet management port and the network ports.
on the Ethernet Management Port
management port supports these features:
(only in switch stacks)
Secure Shell (SSH)
SMNP (only the
ENTITY-MIB and the IF-MIB)
mode—Full, half, and autonegotiation
DHCP relay agent
IPv4 and IPv6
access control lists (ACLs)
Before enabling a
feature on the Ethernet management port, make sure that the feature is
supported. If you try to configure an unsupported feature on the Ethernet
Management port, the feature might not work properly, and the
How to Configure the Ethernet Management Port
Enabling the Ethernet Management Port
Command or Action
Switch# configure terminal
Switch(config)# interface gigabitethernet0/0
Ethernet management port in the CLI.
Ethernet management port.
Switch(config-if)# no shutdown
Ethernet management port.
Switch# show interfaces gigabitethernet0/0
To find out the
link status to the PC, you can monitor the LED for the Ethernet management
port. The LED is green (on) when the link is active, and the LED is off when
the link is down. The LED is amber when there is a POST failure.
What to Do Next
Proceed to manage or configure your switch using the Ethernet
management port. Refer to the
Network Management Configuration Guide (Catalyst 3850 Switches).
System Management Configuration Guide (Catalyst 3850 Switches)
System Management Command Reference (Catalyst 3850 Switches)
Error Message Decoder
To help you research and resolve system error messages in this release, use the Error Message Decoder tool.
Support website provides extensive online resources, including documentation
and tools for troubleshooting and resolving technical issues with Cisco
products and technologies.
security and technical information about your products, you can subscribe to
various services, such as the Product Alert Tool (accessed from Field Notices),
the Cisco Technical Services Newsletter, and Really Simple Syndication (RSS)
most tools on the Cisco Support website requires a Cisco.com user ID and